After putting 2100 miles on my new 2007 990 Adventure (all of them with 91-93 octane), I decided to put some 89 octane fuel in the tank and try the low octane ignition curve. After disconnecting the wires under the seat, I started up the bike. Right away, I noticed the idle rpm dropped from it's normal steady 1500rpm to a variable 1200 to 1300rpm. After about five minutes of idling, the FI light came on and indicated a 18 blink code (lambda probe for front cylinder). I then shut down the engine and reconnected the ignition curve wires. Upon restarting, everything was back to normal. Has anyone else experienced this? One of the reasons I bought the bike was because of it's ability to adapt to various octane levels. In rural Iowa, most gas stations don't offer premium 91 to 93 octane gas - 89 octane with 10% ethanol is everywhere though Any thoughts on what might be happening? I'd really like to be able to use the 89 octane fuel. Thank you.